Koh Dok Mai offers very interesting drift dives along a wall which goes down to 30m. Visibility ranges between 10 and 25 metres. The bizarre rock formations both above and below the water, are completely overgrown with a large variety of coral, home to many species of colourful marine life. The western side of the island features a steep sloping reef. Both blacktip and whitetip reef sharks have been seen here as have many other large pelagic. On the eastern side of the island, there is the opportunity for an impressive wall dive and the exploration of a number of caves and caverns.

The area is rich in invertebrates and has a good representation of tube corals. There are large moray eels and black-and-white banded sea snakes. Besides that, there is a good likelihood that you may see leopard sharks sleeping in the sand at the base of the wall.